Process control bsed manufacturing produces parts that are within a spec range. If the spec range for a cap is 10%, and sampling indicates they are within that range, they don't tweek the process further - it is in control. If (and this is a big if) - a speaker works better with more tightly controlled values, the manufacturer will have to test or buy selected value parts. If a copmpany is selling selected value parts, that means the stuff they sell everyone else is by design farther off nominal. I know that Spica used to measure their caps, and match caps individually to balance out their differences. That is why there are so many caps in a Spica crossover.
Aging of capacitors within crossover networks
Hi folks, I have red that capacitors within loudspeaker's crossover networks show aging with regard to their characteristics (inductance, capacitance, reactance etc.) which has consequences for the crossover itself and finally also for the loudspeaker's sound. Are you familiar with this phenomenon? Does this mean that loudspeakers which are 10 years or older must undergo filter modification (replacement of parts)? What is your opinion?